Email security firm Mimecast says hackers hijacked products to spy on customers

Also covered (among other places) at:

https://www.bleepingcomputer.com/news/security/mimecast-disc...

https://threatpost.com/mimecast-certificate-microsoft-supply...

https://www.computerweekly.com/news/252494698/Mimecast-lates...

Also now covered by Arstechnica:

https://arstechnica.com/information-technology/2021/01/mimec...